Comparing 6 approaches for x-linked hypophosphatemia

Exclusion

• −History of hypersensitivity to any ingredient of any therapeutic monoclonal antibody.
• −For participants who complete the Part 1 EoS visit more than 30 days before starting Part 2 Week 0, eGFR ≥ 60 mL/min at ScreeningScreeningThe checks done before joining, to see whether a study fits.Read more →.
• −Prior history of positive test for human immunodeficiency virus antibody, positive test for hepatitis B surface antigen, and/or hepatitis C virus antibody at Screening.
• −Part 1: Exclusion CriteriaExclusion criteriaThe things that would prevent someone from taking part.Read more →:
• −For XLH participants previously treated with the applicable prior therapy, use within the protocolProtocolThe detailed plan a study must follow.Read more → defined washout periodWashout periodA gap with no treatment, so the previous one clears your system.Read more → prior to ICFInformed consentThe process of being told what taking part involves, then choosing freely.Read more → signature.
• −Have an active infection.
• −Grade 3 or greater nephrocalcinosis as confirmed by renal ultrasound.
• −Uncontrolled diabetes mellitus at Screening.
• −History of known immunodeficiency.
• −History of alcoholism or drug abuse.
• −History of donation of blood within 60 days prior to Screening.
• −Use of any IP or investigational medical device within 30 days prior to Screening, or requirement for any investigational agent prior to completion of all scheduled study assessments.
• −Use of any therapeutic mAb within 90 days prior to Screening.
• −Use of pharmacologically active vitamin D, its metabolites or analogs, oral phosphate for treatment of XLH, aluminum hydroxide antacids, acetazolamide, thiazide diuretics, and/or systemic corticosteroids within 14 days prior to Screening. If the participant takes any of these medications, a washout period of 14 days will be required after signing the ICF and before any other screeening assessments begin.
• −Use of medication to suppress PTH (e.g., calcimimetics) within 2 months prior to Screening and for the duration of the study.
• −Use of denosumab within 6 months prior to Screening.
• −Use of oral bisphosphonates in the 2 years prior to Screening.
• −Use of teriparatide or abaloparatide in the 2 months prior to Screening.
• −Plasma iPTH ≥ 2.5 × ULN at Screening.
• −Participants who are lactating.
• −Current active and symptomatic COVID-19 infection immediately prior to study treatment.
• −Presence or history of any condition that, in the view of the investigatorPrincipal investigatorThe doctor or researcher responsible for running the study at a site.Read more →, places the participant at high risk of poor treatment compliance or of not completing the study, or that would confound safety or interpretation of results.
• −Part 2: Inclusion CriteriaInclusion criteriaThe things you must have or be for a study to consider you.Read more →:
• −Completion of relevant cohortCohortA group of participants sharing a characteristic, followed together.Read more → in Part 1 of the study.
• −Provide a signed informed consent after the nature of Part 2 of the study has been explained.
• −Body weight is at least 40 kg.
• −If taking chronic pain medications (including narcotic pain medications/opioids), must be on a stable regimen for at least 21 days prior to Week 0 of Part 2, and be willing to maintain medications at the same stable dose(s) and schedule throughout the study. The dose must not exceed 60 mg oral morphine equivalents/day.
• −Must, in the opinion of the investigator, be willing and able to complete all aspects of the study, adhere to the study visit schedule and comply with all the assessments.
• −For participants who complete the Part 1 EoS visit more than 30 days before starting Part 2 Week 0, have a corrected serum calcium level of \< 10.8 mg/dl (2.7 mmol/L) at Screening.
• −Part 2: Exclusion Criteria:
• −Use of the applicable prior therapy following completion of Part 1 of the study.
• −Have an active infection.
• −Donation of blood within 60 days prior to Week 0 of Part 2.
• −Use of any investigational product other than KK8123, or investigational medical device, within 30 days prior to Week 0 of Part 2, or requirement for any investigational agent prior to completion of all scheduled study assessments.
• −Use of any therapeutic mAb other than KK8123 within 90 days prior to Week 0 of Part 2.
• −Use of pharmacologically active vitamin D, its metabolites or analogs, oral phosphate for treatment of XLH, aluminum hydroxide antacids, acetazolamide, thiazide diuretics, and/or systemic corticosteroids within 14 days prior to Week 0 of Part 2.
• −Use of medication to suppress PTH (e.g., calcimimetics) within 2 months prior to Week 0 of Part 2.
• −Use of oral bisphosphonates following completion of Part 1 of the study.
• −Use of teriparatide or abaloparatide in the 2 months prior to Week 0 of Part 2.
• −Participants who are lactating.
• −Current active and symptomatic COVID-19 infection, or a history of suffering any long-term sequalae from COVID-19 infection.
• −Presence or history of any condition that, in the view of the investigator, places the participant at high risk of poor treatment compliance or of not completing the study.
• −Negative pregnancy test at Screening of Part 2 and willing to have additional pregnancy tests until the end of the study (female participants only).
• −Be willing to use a method of contraception following local country guidelines while participating in the study and for 30 weeks after the last dose (all sexually active participants of childbearing potential). Women of non-childbearing potential are defined as permanently sterile (i.e., due to tubal ligation at least one year before Screening, hysterectomy or bilateral oophorectomy) or postmenopausal (defined as at least 12 months post cessation of menses without an alternative medical cause). Postmenopausal status of female participants will be confirmed with a Week 0 serum follicle-stimulating hormone level \>40 mIU/mL.
• −Planned or recommended orthopedic surgery during the study.
• −History of traumatic fracture or orthopedic surgery within 6 months prior to Screening.
• −Planned or recommended orthopedic surgery during the study.
• −History of traumatic fracture or orthopedic surgery within 6 months prior to Week 0 of Part 2.